If your home university is one of Trent's exchange partners, you can apply to come to Trent University on exchange through the study abroad application process at your home university. The requirements to be eligible for this program will vary based on your institution, so it is worth doing your research and contacting your university's international/exchange office to discuss the options available to you.
If your home university is not a current exchange partner, you can study at Trent through a Letter of Permission exchange. You can learn more about this by contacting your institution's international/exchange office.